package com.neko.seed.util;

/**
 * 过滤emoji表情与非emoji表情
 * @author suzhenwei
 *
 */
public class EmojiFilter {

	/**
	 * 过滤emoji 或者 其他非文字类型的字符
	 * @param source 需要过滤的字符串
	 * @return
	 */
	public static String filterEmoji(String source) {
		if (!containsEmoji(source)) {
			return source;
		}

		StringBuilder buf = null;
		int len = source.length();
		for (int i = 0; i < len; i++) {
			char codePoint = source.charAt(i);
			if (notisEmojiCharacter(codePoint)) {
				if (buf == null) {
					buf = new StringBuilder(source.length());
				}
				buf.append(codePoint);
			}
		}

		if (buf == null) {
			return "";
		} else {
			if (buf.length() == len) {
				buf = null;
				return source;
			} else {
				return buf.toString();
			}
		}
	}

	/**
	 * 检测是否有emoji字符
	 * @param source 需要判断的字符串
	 * @return 一旦含有就抛出
	 */
	public static boolean containsEmoji(String source) {
		int len = source.length();
		for (int i = 0; i < len; i++) {
			char codePoint = source.charAt(i);
			if (!notisEmojiCharacter(codePoint)) {
				return true;
			}
		}
		return false;
	}

	/**
	 * 非emoji表情字符判断
	 * @param codePoint
	 * @return
	 */
	public static boolean notisEmojiCharacter(char codePoint) {
		return (codePoint == 0x0) || (codePoint == 0x9) || (codePoint == 0xA) || (codePoint == 0xD)
				|| ((codePoint >= 0x20) && (codePoint <= 0xD7FF)) || ((codePoint >= 0xE000) && (codePoint <= 0xFFFD))
				|| ((codePoint >= 0x10000) && (codePoint <= 0x10FFFF));
	}
}
